4.13 Support of NAS signalling using wireline access network

24.5013GPPNon-Access-Stratum (NAS) protocol for 5G System (5GS)Release 17Stage 3TS

A 5G-RG, a W-AGF acting on behalf of an FN-RG or a W-AGF acting on behalf of an N5GC device can use wireline access network to access the 5GCN by using NAS signalling procedures as described in 3GPP TS 23.501 [8], 3GPP TS 23.502 [9] and 3GPP TS 23.316 [6D].

Wireline access is a type of non-3GPP access.

A 5G-RG simultaneously connected to the same 5GCN of a PLMN over a 3GPP access and a wireline access is connected to a single AMF.

5G-RG maintains the N1 NAS signalling connection with the AMF over the wireline access network after all the PDU sessions for the 5G-RG over that access have been released or handed over to 3GPP access.

The 5G-RG connected to 5GCN via NG-RAN is specified in 3GPP TS 23.316 [6D].

When accessing the 5GCN over 3GPP access, in addition to requirements specified for the 5G-RG in the present document, the 5G-RG shall also perform requirements specified in the present document for a UE accessing 5GCN over 3GPP access. When accessing the 5GCN over wireline access, in addition to requirements specified for the 5G-RG in the present document, the 5G-RG shall also perform requirements specified in the present document for a UE accessing 5GCN over non-3GPP access. If a requirement specified for the 5G-RG in the present document contradicts a requirement specified for the UE in the present document, the 5G-RG shall perform the requirement specified in the present document for the 5G-RG.

For the scenario of FN-RG, which does not support N1 mode, the W-AGF acting on behalf of the FN-RG exchanges NAS signalling messages with an AMF.

For the scenario of N5GC device, which does not support N1 mode, the W-AGF acting on behalf of the N5GC device exchanges NAS signalling messages with an AMF.

In addition to requirements specified for the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) in the present document, the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) shall also perform requirements specified in the present document for a UE accessing 5GCN over non-3GPP access. If a requirement specified for the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) in the present document contradicts a requirement specified for the UE in the present document, the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device) shall perform requirement specified in the present document for the W-AGF acting on behalf of the FN-RG (or on behalf of the N5GC device).

The PDU session authentication and authorization procedure is not supported in a PDU session established by the W-AGF acting on behalf of the FN-RG or on behalf of the N5GC device.

The W-AGF acting on behalf of the N5GC device requests the establishment of a PDU Session on behalf of the N5GC device upon registration. Only one PDU session per N5GC device is supported.

A 5G-RG or an FN-RG provide a non-3GPP access network to UEs. A UE connected to a non-3GPP access network provided by the 5G-RG or the FN-RG can access to the 5GCN via the N3IWF or via the TNGF as described in 3GPP TS 23.316 [6D].

The 5G-RG or the W-AGF acting on behalf of the FN-RG shall indicate "ANDSP not supported by the UE" in the UE policy classmask IE during the UE-initiated UE state indication procedure as specified in subclause D.2.2.